1. Field of the Invention
The present invention relates to an image processing apparatus and, more particularly, to an image processing apparatus for executing an image processing of image data picked up by, for example, a light field camera.
2. Description of the Related Art
An imaging apparatus using a method called “Light Field Photography” is proposed (the Official Gazette of Japanese Patent Application Laid-Open No. 2009-124213 or the Official Gazette of Japanese Patent Application Laid-Open No. 2012-129654). The imaging apparatus is constructed in such a manner that an ML array constructed by a plurality of microlenses (hereinbelow, referred to as MLs) is used and, in addition to intensity distribution of light on a light receiving surface of an imaging element, directional information of the light can be also obtained. It is also constructed in such a manner that after the image pickup, by using the obtained intensity distribution and directional information of the light, an image can be reconstructed on the basis of a set arbitrary viewpoint and a set arbitrary focus position. In the Description, such an imaging apparatus is called “light field camera”. In the light field camera, in addition to information of a position where the rays of light from an object enters an imaging plane, light ray information including information of an angle of incidence is obtained. The light ray information is called light field data (hereinbelow, referred to as LF data). An image in which the focus position of the image is changed after the image pickup can be reconstructed by using the LF data.
In the light field camera, since a ray of light corresponding to one pixel of a camera in the related art is divided by the MLs and handled as a plurality of pixel data, an amount of the data increases in proportion to the number of division. For example, assuming that the division number is equal to (5 in the vertical direction×5 in the lateral direction), the data of (5×5) pixels per ML is obtained, so that the data amount is increased by 25 times. As mentioned above, there is such a problem that the data amount of the LF data is extremely larger than an amount of data of the image picked up by an ordinary camera.
Therefore, in order to compress and store an information amount of the extremely large LF data, an importance is attached to a compression encoding technique.
The invention is made in consideration of such a point and it is an aspect of the invention to provide an encoding method suitable to compress an information amount in, for example, LF data or the like and to provide an image processing apparatus or the like for encoding, for example, LF data or the like by the proposed encoding method.